标题： 超快磁光实验中的大自旋积累信号 显示英文标题

标题： Large spin accumulation signals in ultrafast magneto-optical experiments

摘要： 磁光技术已成为自旋电子学中的关键工具，使在超快领域研究自旋动力学成为可能。 该领域的一个主要挑战是准确分离自旋输运现象对磁光信号的贡献与局部磁化动力学的贡献。 被输运和积累的自旋的贡献长期以来被认为比磁化贡献小几个数量级，因此以前解析这些信号的方法依赖于特定的实验设计，通常包括厚金属层。 在此，我们提供了实验证据，证明在某些条件下，超快自旋积累的磁光信号可以与标准超快去磁实验中磁层的信号相媲美，甚至超过它。 我们的发现为获取和分离这些自旋积累提供了新框架，使得能够对输运的自旋和/或轨道角动量进行时间和深度依赖的探测。 显示英文摘要

摘要： Magneto-optical techniques have become essential tools in spintronics, enabling the investigation of spin dynamics in the ultrafast regime. A key challenge in this field has been to accurately isolate the contributions to magneto-optical signals of spin transport phenomena from the local magnetization dynamics. The contribution of transported and accumulated spins was long believed to be orders of magnitude smaller than that of the magnetization and thus previous approaches to disentangle these signals have relied on specific experimental designs, usually including thick metal layers. Here, we present experimental evidence demonstrating that the magneto-optical signal from ultrafast spin accumulations can, under certain conditions, be comparable to or even exceed that of the magnetic layer in a standard ultrafast demagnetization experiment. Our findings provide a new framework for accessing and isolating these spin accumulations, allowing for time and depth dependent probing of transported spin and/or orbital angular momentum.